If you arrive by plane at Bangui's airport you don't have to go far to see evidence of the disastrous situation in the CAR. Thousands and thousands of displaced people are living on the edge of the tarmac, some even sleeping under abandoned airplanes. Faces are pressed against the barbed wire that French peacekeepers have hurriedly strung-up along the edge of the runway.

Inside the camp the mood is very tense. A young man tells me, 'everyone here is a Christian. If a Muslim comes here we'll kill him, just as they kill us without mercy'.

Another team of journalists, with a driver who is identified by the crowd as a Muslim, have to plead for his life after he's seized by a furious mob. Eventually, a senior clergyman has to intervene, pleading with the crowd to release the unfortunate man.

Conditions in the camp are squalid. The heat is stifling, the sickly stench of diarrhoea in the air. Families are crowded under canvas and plastic.

The aid organisation Medecins Sans Frontieres (MSF) is hurriedly vaccinating children for measles, to prevent a potentially deadly epidemic. Last week, they suspended their activities for several days because of gunfire around their clinic.

All but collapsed

Elsewhere in Bangui the mood is tense. The state has all but collapsed - schools are closed, hospitals limp on only because of the support of foreign aid organisation.

There is sporadic shooting at night, when the streets are deserted. But on Friday crowds came out onto streets near the centre to demand the resignation of President Michel Djotodia. Anti-Balaka armed men, wearing amulets and charms, set up roadblocks.

French and African peacekeepers roam the streets in jeeps and armoured personnel carriers. They hope their patrols will reassure people, but they can't be everywhere at once. And we hear new reports of massacres in the countryside outside Bangui.

This is, after all, a vast country with porous borders. A few thousand peacekeepers, no matter how dedicated or professional, can do little. There is a very dangerous power vacuum in the CAR.

The international community could step up its presence, but any lasting solution needs to be homegrown. I ask one observer whether there's anyone who could unify the country. He looks at me as if I'm stupid. "We don't trust any of our leaders," he says.